楽天の在庫API（InventoryAPI）を使ってPythonで在庫更新をRPAしよう

import zeep, base64
import requests
import time
import urllib.request
import urllib.error
import defusedxml.ElementTree as ET
import datetime

#楽天api
serviceSecret = 'hogehoge'
licenskey = 'hogehoge'
b64 = serviceSecret + ':' + licenskey
b64_en = base64.b64encode(b64.encode())
api_key = b'ESA ' + b64_en
api_key_str = str(api_key)
api_key_str = api_key_str[2:]
api_key_str = '' + api_key_str[:-1] + ''

url = 'https://api.rms.rakuten.co.jp/es/1.0/inventory/ws'

# 設定値
requestURL = url 
headers = {'Content-Type': 'text/xml;charset=UTF-8'}
method = 'POST'
shop_url = 'hogehoge'


def put_item_stock(shop_url, item_id):
    body = """<?xml version="1.0" encoding="UTF-8"?>
    <SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" 
     xmlns:ns1="java:jp.co.rakuten.rms.mall.inventoryapi.v1.model.entity"
     xmlns:ns2="https://inventoryapi.rms.rakuten.co.jp/rms/mall/inventoryapi"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:ns3="java:language_builtins.lang">
    <SOAP-ENV:Body>
    <ns2:updateInventoryExternal>
    <ns2:externalUserAuthModel>"""
    body += api_key_str
    body += """ 
    <ns1:userName>?</ns1:userName>
    <ns1:shopUrl>"""
    body += shop_url
    body +="""</ns1:shopUrl>
    </ns2:externalUserAuthModel>
    <ns2:updateRequestExternalModel>
     <ns1:updateRequestExternalItem>
      <ns1:UpdateRequestExternalItem>
       <ns1:inventory>50</ns1:inventory>
       <ns1:inventoryType>2</ns1:inventoryType>
       <ns1:itemUrl>"""
    body += item_id
    body += """</ns1:itemUrl>
       <ns1:inventoryUpdateMode>1</ns1:inventoryUpdateMode>
    </ns1:UpdateRequestExternalItem>
    </ns1:updateRequestExternalItem>
    </ns2:updateRequestExternalModel>
    </ns2:updateInventoryExternal>
    </SOAP-ENV:Body>
    </SOAP-ENV:Envelope>"""

    response = requests.post(url, data=body, headers=headers)
    xml_data = response.content.decode('utf-8')
    return xml_data
    
if __name__=="__main__":    
    item_id = 'hogehoge'
    put_item_stock(shop_url, item_id)